Water availability underpins both socioeconomic development and ecosystem sustainability. This study investigated the surface hydrological characteristics of the Bennihalla Basin, spanning Dharwad and Gadag districts in a hard rock terrain dominated by Archaean meta sedimentary rocks (Meta Greywackes and Granitoids). Thirty-seven soil samples were analyzed for moisture content, organic matter, grain size distribution, and mineralogy using field and laboratory methods. Soil moisture ranged from 16.6% to 38% (mean 28.6 ± 5.9%), and organic matter ranged from 1.2% to 6.72% (mean 3.98 ± 1.54%), with a moderate positive correlation (r = 0.35). Particle-size analysis indicated that silt + clay comprised an average of 80.8% of the soil mass, with coarse, medium, and fine sand fractions averaging 4.84%, 6.50%, and 7.86%, respectively. XRD analysis showed quartz (25–55%), feldspar (10–25%), and calcite (5–15%) dominating coarse-textured, well-drained soils, while Montmorillonite (10–30%), Kaolinite (5–20%), Illite (5–15%), and Gibbsite (2–8%) occurred in finer soils with higher water retention. Smectite-rich zones exhibited higher moisture storage but lower infiltration rates, whereas Kaolinite- and Quartz-rich uplands drained rapidly and stored less water. These findings highlight mineralogical control on infiltration–runoff dynamics, offering site-specific guidance for flood mitigation and watershed management in semi-arid hard rock regions.
